Abrading unit



J ne 6, 1953 J. M. RADABAUGH ABRA DING UNIT 2 Sheets-Sheet '1 Filed July 27, 1951 John M. Radabaug/z INVENTOR.

9 BY an Jun 16, 1953 J. M. RADABAUGH 2,641,878

' ABRADING UNIT Filed July 27, 1951 2 Sheets-Sheet 2 John M. Radabaugh,- zzvmvron.

Fig.6 a 6 Patented June 16, 1953 OFFICEI 2,641,878? ABit'iADINGfU NIT' JohniMzzRadabaugh, Mount wernonyohioe Amintafianfiisrzr, 1951; strait NB. 2381882 Claims (GEM-L197)"- This invention relates tonew 'and useful 1m;

provements'-an'd-structural refinements fin ahrad ing units; more particularly; abra'dihg devices wherein a'sheet of abrasive=materia1-is mounted I economical manufacture.

with the-abovemore important objects and features in view, and such other-obj ects and "fe'a tu'res as-may become apparent 'as this *sp'eciflcag tion proceeds, the 'invention'- consists *essentially f: the arrangement *andconstructi'omof {parts'a's illustrated in-'- the accompanying" drawings," in

which: V

Figure -1 is arear elevational view of the -"in--- ventiony' t V I Figure 2 is a fragmentary sectional viewftaken substantially on the plane of the line 2 2 of Fig ure :1;

Figure- 3 is-a fragmentary view oftheannular' clampingV=member; part1y broken away: 4

Figure 4 is a rear elevational vie'wg partly broken awayfiiliustrating a modified mbodimentfof the" invention f.

Figure 51s a sectional de'taiiftakeirsuhstantially in plane of the line 5-5 0?Figure'i and illiis tratingx-thevunit in its clamped position;

Figure 6 is a sectional detail, similar to that shown in Figure 5, but illustrating the unit in-= its 7 released position; and

the principal 21L disl; *l 2 is provid'edf and the n'ieans for sustainin'g'fthesheet 22"in position-on the disk I2 inean annular clamping member 25*wh ich is disposed at theperiphery'of the disk" l2 and is provided withian inturned; annular flange 28 to clamp the sheet 22 *against' the seat 2G, as'is clearly?showrfin Figure 2. The clamping member 2 SIproj c ots?rearwardly beyond the rear face I 6 of-the disk l 2 andis formed with an annular groove" 39 which is open at the-inner side there of, so as to receivejtherein'theouter end portions of a; setofblamping fingers *32'. The "fingers are disposed adjacent the rear face it of' the 'disk l2 and are arranged iii-integral pairs; connected to- Figure '1 -is. aefragmentary viewpofrone of the levers used in the embodimentof Figure 4.

Like reference characters are:- employed t ignate l'ikepartsin the specificationiand throughout; the several-views.

Referring'now to "the accompanying drawings indetaii, more-- particularly to "Figures 132 :and 3, the invention -consistsof an 'abradinggiinit which: is*designated' --general1y?by';the reference character-"1 I] and embodiesin-"itsconstruction a rotary diski 2- havinga front face! 4 and a rear face I6, thereanfaceof. theadiskwbeing provided with an axial shaft' membrWBwhich is screw threa'dediand carries an. actuating nut 2U=vvhich will: he: hereinafter. describeda t Azcircularrabrasive sheet 22 is positioned against the front face 14 of the disk l2 and the marginal edge portion of this sheet is disposed in a rearwardly offset, annular seat 24 with which the marginal edge portion of the frontface of they disk 1 2'5 gethr by a -big-htportion 34 (see-Figure 1) the bight 'porti'on of the severalpairs of fingers beingrotatively- -journa11e din provided-ona spider38-I s v The pi'd'ertfii -isrotativelvfmounted upon'a diametrical y reduced portion- 4%? of the aforementienedaamaun nut "-2 i1 and is sustained thereon by a snap ring 42, and it will be observed that intermediate portibns offthe finger's 32 engage a fulru'mf'ri-ng id providedontherear face of the pairs of bearings '36 lt will be 'apparent from the foregoing that when the nut 26 is tightened on the screw threadedshaftfl 8; the spider '38' 'will beforced'downweirdly toward-the disk'meniberd 2 and; with the ring- 44 acting=as a-fulerumfor'the fingers 32';- the outer ends 'of the fingers; seated "in the groove 31]," wil=l press th clamping member 26' rearwardly as showniat tepthus pressing theiiange 28 and i the edge portion of the abrasive sheet 22 against the seat124l$ On the other hand, when the actuating nut 20 isuloosened 'forr the shaft" I8," the-pressure of the clamping member 25 onthe alorasivesheet"22 will be relaxed'wand' suitable springs id-are positioned on thei inner" end portions of the fingers 32" and abut" thefspider 1-38 "as at ia; so as -to assist inre1axing'the -pressure of 'the clamping "member'- Irirxother' w'o'rds,- the positionflth'eisprings' w caus .the fin'gers to relax wherr the nut 2 Gris loose. I

Ref-erringtncw to the modified em'bodiment of I the: ainvention '-i1lustrated in the accompanying e "rotary disk- 6- herein carries the'abrasive sheetBZ on the front face thereof and is provided at its periphery with anannular clamping member 64 similar to the aforementioned member 25. The member (55 has an It annular groove 56 to receive outer end portions of pairs of fingers 68, the fingers in each pair being connected together by a bight portion 19 which is rotatably journalled in a suitable bearing provided intermediate the ends of a clamping lever 12.

Of course, a separate clampin lever is provided for each pair of the fingers, and suitable collars 74 are provided on the bight portion ill at the opposite sides of the bearing on the clamping lever, to prevent the bight portion from sliding or shifting in its hearing.

The fingers 68 have intermediate portions thereof engageable with a fulcrum ring 76 provided on the rear face of the disk 69, and the ring on said disk and engageable with intermediate portions of said fingers, outer ends of the fingers being disposed in said groove, and an actuating nut provided on said shaft member and inner ends of the levers 12 are rotatably journailed by means of transverse pins 13 in bearing brackets 85) affixed to the rear face of the disk.

As will be clearly apparent from Figures 5 and 6, when the clamping levers 12 are swung downwardly toward the disk 69, the outer ends of the fingers 98 will be projected into the groove 66 and, by virtue of the fulcrum ring It, the clamping member 5 will securely hold the abrasive sheet 62 against the front face of the disk, while on the other hand, by swinging the levers 12 upwardly away from the disk 69, as shown in Figure 6, the outer ends of the fingers 98 will be withdrawn from the groove 86 and the clamping member 64 and the pressure of the latter on the abrasive sheet 52 will be relaxed.

Means are provided for locking the levers ii in their clamping position, the means consisting of suitable hooks 82 which are pivoted as at 84 to the rear face of the disk 68 and are receivable in slots 86 with which the levers 12 are provided,

suitable springs 88 being employed for pressing the hooks 82 into engagement with the levers '12 when the latter are in their clamping position.

The disk 69 may be mounted upon a flange 93 vi of a drive shaft 92 in any suitable conventional manner.

It is believed that the advantages and use of the invention will be clearly understood from the foregoin disclosure and accordingly, further description thereof at this point is deemed unnecessary.

While in the foregoing there has been shown and described the preferred embodiment of this invention, it is to be understood that minor changes in the details of construction and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as claimed.

Having described the invention what is claimed as new is:

1. In an abrading unit, the combination of a rotary disk having front and rear faces and a peripheral edge, a circular abrading sheet positioned on the front face of said disk, an annular clamping member disposed at the peripheral edge of the disk and movable forwardly and rearwardly relative thereto for clamping a marginal edge portion of said sheet against the front face of the disk said clamping member projecting beyond the rear face of said disk and being pro.- vided with an annular groove open at the inner side thereof, and means on the rear face of the disk and engaging said clamping member for moving the same forwardly and rearwardly, said means comprising a screw-threaded shaft memengaging said spider.

2. In an'abrading unit, the combination of a rotary disk having front and rear faces and a pcripheral edge, a circular abrading sheet positioned on the front face of said disk, an annular clamping member disposed at the periphera1 edge of the disk and movable forwardly and rearwardly rela-- tive thereto for clamping a marginal edge portion of said-sheet against the front face of thedisk, said clamping member projecting beyond the rear face of said disk and being provided with. an annular groove open at the inner side thereof, and means on the rear face of the disk and engaging said clamping member for moving the said disk, a set of fingers having inner portions thereof pivoted to said levers and outer ends disposed in said groove, and fulcrum means provided on said disk and engageable with intermediate portions of said fingers.

3. The device as defined in claim 2 together with means for locking said fingers in a clamping position. I

a. In an abrading unit, the combination of a rotary disk having front and rear faces and a peripheral edge, a circular abrading sheet positioned on the front face of said disk, an annular clamping member disposed at the peripheral edge of the disk and movable forwardly and rearwardly relative thereto for clamping a marginal edge portion of said sheet against the front face of the disk, said clamping member projecting beyond the rear face of said disk and being provided with an annular groove open at the inner side thereof, means for moving said clamping member rearwardly, said means including radial fingers having outer ends engagea'ble with said groove, a fulcrum ring secured to the rear face of said disk and engageable with an intermediate portion of each finger and mechanism operatively connected to the inner end of each finger to move the same toward the disk.

JOHN M. RADABAUGH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 361,399 Davis Apr. 19, 1887 l9,950 Rodgers et a1 Apr. 7, 1891 594,320 Bonniwell Nov. 23, 1897 619,921 Adams Feb. 21, 1899 878,269 Beck Feb. 4, 1908 905,464 Sadler Decjl, 1908 923,865 Lippincott June 8, 1909 1,623,521 Bennington Apr. 5, 1927 FOREIGN PATENTS Number Country Date 7,249 Great Britain Jan. 11, 1906 315,917 Germany June 27, 1918 

